Clinical and sonographic determinants of Xpert MTB/RIF positivity in cervical tuberculous lymphadenitis: a retrospective study

Background Xpert MTB/RIF is recommended for rapid microbiological testing of lymph node specimens, but its positivity in cervical tuberculous lymphadenitis may depend on lesion characteristics and specimen composition. We investigated clinical and sonographic factors associated with positive Xpert MTB/RIF results in ultrasound-guided biopsy specimens. Methods This single-center retrospective study included 334 patients who underwent ultrasound-guided lymph node sampling between January 15, 2020, and February 24, 2025 and were clinically diagnosed with cervical tuberculous lymphadenitis. Patients were classified as Xpert-positive or Xpert-negative. Clinical variables, sonographic features, and specimen type were analyzed using univariable and multivariable logistic regression. Results Xpert MTB/RIF was positive in 231 of 334 patients (69.2%). Positive results included 217 rifampin-susceptible, 12 rifampin-resistant, and 2 rifampin-indeterminate results. In multivariable analysis, lymph node diameter ≥1.5 cm (adjusted odds ratio [aOR], 2.20; 95% confidence interval [CI], 1.26-3.94; P = 0.006) and pus specimens (aOR, 6.38; 95% CI, 3.39-12.83; P < 0.001) were independently associated with Xpert positivity. Positivity rates were 81.5% for lymph nodes greater than 1.5 cm and 90.2% for pus specimens. Conclusions Larger affected lymph nodes and pus specimens were independently associated with higher Xpert MTB/RIF positivity. During ultrasound-guided sampling, liquefactive necrotic areas should be preferentially targeted when safely accessible. Trial registration Not applicable; this was a retrospective observational study.